The present invention is directed to an amplifier for telephone handset. In particular, the invention is directed to an amplifier for a telephone handset which is directly connectable to existing standard telephone line cord without altering the cord in any manner.
Amplifiers for telephone handsets are well-known. For example, see U.S. Pat. Nos. 3,254,160 and 3,830,979. Conventional amplifier handsets, however, suffer from several serious deficiencies. Typically, to install a conventional amplifier, it is necessary to alter the standard telephone line cord by severing the receiver input signal lines and connecting the same to a junction at the transmitter cup. The receiver input signal lines must be color coded at the transmitter junction to properly connect the same to the amplifier. Thus, the conventional amplifier is sensitive to the receiver input signal line polarity, and properline polarity must be observed for each of the amplifier circuit interconnections.
Installation of a conventional amplifier for a telephone handset is slow and cumbersome. Unless the receiver input signal lines are properly color coded, installation must proceed step by step according to relatively complicated wiring schematics. In either case, the input lines may be improperly connected in respect to polarity by an unskilled repairman. Moreover, to properly install the conventional amplifier, the standard telephone line cord must be altered or special line cord provided in replacement further adding to the costs of installation and repair.
To date, the need for an amplifier which can be quickly and conveniently installed in a telephone handset without regard to receiver input signal line polarity using existing standard telephone line cord has not been met.